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ale and other articles which er I U ITE "rn'rns Arrests IMPRQJEMENT iNlViAKlNG CHlLLED CASTINGS.

Specification forming part of Letters Patent No. 50,680, dated October ill, 1865.

To all whom it may concern Be it known that we, Gnoscs W. BcL MAN and. WILLIAM NEEMES, of the city of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful improvement in the Making of Chilled Castings; and we do hereby declare the following to be a 'full, clear, and exact description thereof, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a perspective repr scntution oft-a chill through a: m, Fig. l, showing the interior of the chill.

In the several figures letters denote similar parts.

'In the manufacture oi rolls lling rnetdesigned to have a surface harder and snsccptihlcot' a finer polish than ordinary cast-iron it is usual to cast the body of the roll, or that part of the casting which is to be hardened, in a chill.

This chill consists (in the case of casting rolls) of a heavy hollow iron cylinder, the cavity of which is of the shape and size of the body of the roll to be castin it, the necks of the roll at each end being cast in sand-molds in flasks attached to the chili. These rolls are cast with the exisof the chill in a vertical position. The efi'ect of the chili is to abstract the heat rapidly from the surface of the metal cast in it,so as to cool it so much the more rapidly on the surface than in the interior ofthe casting as to form a hard crust outside, or, as it is called a chilled -surface.

The difficulty encountered in casting rolls .in a chill is that as the large mass of iron composing the chill becomes heated by the molten metal which it contains it expands considerably, thus increasing the diameter of its cavity, not, however, until it has formed a thin hard crust or skin on the surface of the casting. This crust is too thin andweak to retain its shape unless supported by the sides cfthe chill, owing to the great pressure of the chess of yet .fiuid metal in the interior of the crust; but as the chill expands it leaves the surface of the casting, which bursts, allowing the melted metal to run more-or less into the space thus formed,and the result is that the roll is ruined. This does not always occur',-but it happens so frequently, and is so difi'icult to be prevented, as to increase greatly the cost of manufacture oi'chilled rolls, especially those'of large diain eter. The same difiiculty occurs, although not to a like extent, in casting railroad-car wheels, the trend of which is cast against'a chill, and other lighter articles of chilled castings but in these comparativelylighter articles thereis 'ther additional difiiculty of the warping of the chill for casting chilled rolls-w, thelonifir part" being represented as broken away to show the interior. Fig, 2 is a horizontal section of the chill iron the heat and the consequent inis shaping of the casting.

lliese ohstaclcs to the successful manufactureol'cliilled,.i-olls and other chilled castings "it is the objsu'i/ 01' our inremrlon'rtcovercome; and we, attain this result by casting articles which are to bc chilled in a thin metallic chill and surrounding the chill with water, whereby the chill is kept sutliciently cool to prevent its expanding so much as to damage the cast ing, and the depth of thechilled surface may be increased.

To enable others skilled in the art to use our improvement, we will proceed to describe its use and operation as applied tothe casting of chilled rolls.

The several figures of 'the drawings represent the chill which we use, in which a is the chill, which is a hollow cast-iron cylinder, the

interior diameter (or cavity) of which is the size of the body of the roll to be cast in it. To this the flasks for casting the neck of the rolls are attached in the usual manner. The chill, instead of being, as is usual, six or seven inches in thickness all round, is onlyfrom one to two inches thick.

Around the circumference of the chill, at the top, is a flange, b, cast together with the chill,

and around the bottom of the chillisa similar flange, b, of the same width. These flanges I) 1) form the top and bottom of the cavity a, which is formed around the chill c by a cylindrical casing, d, made of boiler-plate, which may be riveted to the flanges b b or held in place, as shown in the drawings, by a band, 6,

at each end of the chill, drawn tightly around the casing over the flange by a clamp screw, s. In the bottom of the cavity a of the chill, resting on the lower flange, b, and extending the casting. a

2 I emcee 1 j around it,-.is a pipe; one end of which conneets with a short pipe, 9, which enters the cav-. aity around thechill through the lowerflange,

b, and the other. end of which reaches nearlyto the pipe g. :The pipe surrounding the chill,

' as. before. stated, isopen. The circular pipe f hasholes 'i'hored in its upper side at short in- -'tervals all around, so as to admit the water at ts-.-v 41 .teevrrs aenflsf W999i".

isian exit-pipe, h.- v

The, chill, being thus constr.ucted,'is leper ated'as follows: Whenthe roll is to be castin it, and while the molten metal is being poured in, a stream of cold water is admitted from below throughthe pipeg, which traverses the, circular pipe f, passing'out; at the open end,

. and also at all the intermediate holes, i. The obje ct of introducing the water through the circular perforated pipe. f isto prevent it-strikingth'e side-of the chill at one pointand cool iug it irregul rly. The-water thus flowing in at the bottom of the chill passes out at the exit-,1

,pipe h at the top, and the continual str eatn., serves to carry ofl' the heat from thecliill; kee

ing it sufficiently cool to prevent any undue expansion, and alsogaiding materia'llyin chi ll-;

ing the surface of the casting.- t

- The thickness oft-he chill willdepeudon-its diameter or the size of casting to be made in itL: The rapidity'with which the cold wateris" caused to flow through the cavity 0 of the chill; v

will regulatethe-degr eeofchill to be giycuto' In, castingfcar-wheels orfl-any other, castings.

to" be chilled hollow chillsfarej to' henscil t through the cavity of which astream of water as hereinbefore described. Y

is allowed to pass in the manner substantially In place of surrounding the chill with a'casing, "d, and passing a current of water around it it-may'be immersed in a reservoir of water, althongh'the plan described is preferable.

We are aware that hollow flasks have been used for the purpose of heating the mold in "'which'the casting is made, and we do not claim,

broadly, the use ofsuch hollow flasks or molds;

but 7 r v\Nhat we do claim as our invention is-- Theuse of thin metallic molds or chills for makin g chilled rolls,- shaftiugs, and other large. castings when the exterior ofthe chill in which the casting is formed is surrbundedwith-cold waterfor the purpose of v ahstractin g the heat from the surface of the-roll, thus preventing .thewarping otthe.chill, 'an'd of chilling the misting from the surface more rapidly and to a r greater depth,& fi n'stant istream of cold water ibeingapp'l'ied to takeithetp ace ofthat-which,

having become 'heated -is allowed to escape, in

themanner.' substantially; as hereinbefore deal 'n testimony whereof wefihe'said GEORGE- .W.; BOLLMAN. and Wrnnrnnrlinmtns; ha've "1on0. WIB'QLLMAN.

,- W PPI MI EE ,JoHN Ponnocx, v 

